Prior art stereoscopic 3D measurement methods determine the horizontal shift, also referred to as “disparity” or “pixel shift,” between corresponding image segments of Left (L) and Right (R) eye images using one or more of the following methods:
1) Finding the corresponding image component that is in both the L and R image and measuring the difference in pixels in the horizontal position from either edge of the image. The resulting difference is the pixel disparity.
2) Using a first horizontally adjustable vertical line to mark an image segment on one image (L or R) and then using a second horizontally adjustable vertical line to mark the corresponding image segment in the other image. A readout then indicates the difference in the horizontal offset of each vertical line as the disparity.
The use of these methods can be augmented by one or more of the following methods to combine the L and R images into a single image to allow the disparity to be measured as in the methods above but using only a single image:
1) Subtracting the two images (L-R or R-L) to create a difference image where the disparity and edge intensity create a non-zero difference to more easily identify the image segments for disparity measurement.
2) Summing the images (either as-is, or with edge enhancement or detection) to create a double image to more easily identify the image segments for disparity measurement.
3) False coloring the L and R images as in anaglyph 3D to create a super-imposed image of L and R where the color fringe more easily identifies the image segment offset due to disparity.